The present invention relates to a liquid for contact lenses. More particularly, the present invention relates to a liquid for contact lenses which can be preferably used for preservation, cleaning and disinfection of contact lenses.
In general, most of contact lenses, in particular oxygen permeable hard contact lenses, are prepared by using a silicone component. Accordingly, the lens surface becomes hydrophobic and wettability of the lens at initial wearing is poor. As a result, wearing sensation is lowered and sight cannot be sufficiently recovered.
Therefore, in order to maintain surface wettability during preservation when not being worn, the above oxygen permeable hard contact lens is subjected to surface treatment or immersed in a preserving solution such as physiological sodium chloride solution.
However, in the case that a contact lens is preserved in such physiological sodium chloride solution, the base curve which is one of the important standards of a contact lens sometimes varies.
For instance, bacteria may propagate in a preserving solution during preservation of a contact lens. Accordingly, in order to prevent bacteria from propagating, an antiseptic is added to the preserving solution.
However, the antiseptic effect of the antiseptic is sometimes insufficient, or some of the antiseptics are poor in safety and durability. Accordingly, such antiseptics are not effective for preventing the propagation of bacteria.
In particular, in the case when a soft contact lens is immersed in the above preserving solution containing an antiseptic, the antiseptic sometimes adheres to the surface of the soft contact lens or is sometimes captured in the inside of the lens. Accordingly, it is desired that there is developed a method comprising using a polymerized antiseptic.
An object of the present invention is to provide a liquid for contact lenses, which can substantially decrease the variation of the base curve of a contact lens, in particular an oxygen permeable hard contact lens during preservation, and which shows an excellent antiseptic effect, an excellent antibacterial effect and durability of these effects.
This and other objects of the present invention will become apparent from the description hereinafter.